If you are looking for a cheap, monitored home security system, make sure you stay clear of the free security systems. I'm sure you have seen the ads on the internet claiming that you can get a "free" home security system installed.

What you basically get is an all-in-one wireless security system. This means that the control panel, keypad, alarm and dialer are all located in one place. You will also get one wireless door or window sensor and one wireless motion sensor.

What these companies don't tell you is that if you want additional sensors for your doors and windows, it will cost you extra. The cost can run you between $50 and $90 for each sensor.

You also have to sign a long-term contract for the company to monitor your "free" system. The long-term contract can be for several years. And if you're not paying attention, the monitoring company can automatically renew your contract if you don't cancel it.

It doesn't take much work to install a wireless security system, so their technicians are usually not trained professionals. You can also expect to pay an activation fee just to get your system working.

Because these systems are all-in-one, they are pretty vulnerable. If an intruder breaks into your home and disables your keypad, he not only destroys the keypad, but he destroys the control panel, alarm and dialer at the same time.

If you buy a home security system from a more reputable monitoring company, they will install your control panel in a separate place inside your home, usually in the basement. The dialer will be located inside the control panel.

If an intruder tries to break the keypad that's usually located near your front door, the control panel won't be affected. The alarm will still work and the dialer will contact the monitoring station to notify them that there is a disturbance at your home.

The "free" home security systems are also vulnerable to false alarms because wireless systems are not as reliable as wired ones. Many cities will charge you a lot of money if the emergency services have to keep coming out to your home for false alarms.

If you go with a more reputable company like ADT or Broadview Home Security, you can expect to pay around $200-$500 for the security system. They usually will install it for free. After that, you will pay around $35-$50 for monthly monitoring fees.

The system that they install will be more secure, have better monitoring services and will give you more peace of mind than the so-called "free" wireless systems.